Not Applicable
Not Applicable
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1. Field of the Invention
This invention pertains generally to interconnected computer networks, and more particularly to an ultra-low latency, multi-protocol, optical router with a peta-bit per second total aggregate switching bandwidth.
2. Description of the Background Art
Telecommunications is currently undergoing a large-scale transformation. The explosive growth in the Internet, multi-media services, and computer communications is demanding a national network that can accommodate the entire amount of traffic in a cost effective manner. Advances in wavelength division multiplexing (WDM) technology have ushered in networks that are orders of magnitude higher in transmission bandwidth than existing networks. The xe2x80x9cNext Generation Internetxe2x80x9d (NGI) is expected to benefit from the high capacity and versatility of the multiwavelength optical networking technology. A number of commercial vendors have embarked on building next-generation core routers incorporating large scale electronic switch fabrics. While such routers demonstrate impressive aggregate switching capacities of terabits-per-second, however, it is evident that the power consumption and the physical size of these routers will limit scalability of the electronic routers much beyond the terabit regime.
FIG. 1 illustrates the typical switching architecture of the core in terabit routers currently being investigated by the industry. One of the key limiting factors in scaling these large electronic routers lies in power requirements. Due to the high-speed and high-connectivity requirements of such routers, they must employ optical interconnections between the transponders at the edges and the electronic switch fabric. The power requirements scale as 3aN+bN2 where N is the product of the total number of ports and wavelengths, a is the power dissipation per transponder, and b is the power dissipation per cross-point in the electronic switching fabric. This assumes a crossbar switch for the electronic switching fabric; however, the Banyan or Benes architecture will include a term which is approximately (bNlog2N) instead of (bN2). Typical transponders dissipate typically 2.0 Watts for 2.5 Gb/s short reach, and higher for higher speed and longer reach transponders. Accordingly, the total power requirements for a terabit electronic router typically exceed 10 kW for a long reach ( greater than 50 km) and high bit rates ( greater than 2.5 Gb/s).
Therefore, there is a need for an ultra-low latency, multi-protocol, optical router with a peta-bit per second total aggregate switching bandwidth that is physically compact and has low power requirements. The present invention satisfies those needs, as well as others, and overcomes deficiencies in conventional router technology.
In general terms, the present invention comprises a revolutionary ultra-low latency optical router with a peta-bit-per-second total aggregate switching bandwidth. Further, the optical router of the present invention will scale to a total connectivity of 1024 by 1024, and beyond this value by modular upgrades. The invention effectively utilizes advanced optical technologies to achieve such high capacity with two to three orders of magnitude less volume and power requirements than the electrical router counter part.
By way of example, and not of limitation, the core of the inventive optical router also serves as a universal engine to other optical routers being developed by vendors and researchers today. With proper attachment of middleware modules, the inventive optical router can function in the context of circuit-switching, flow-switching, burst-switching, and packet-switching. In particular, an optical-label (OL) switching implementation of the inventive optical router provides the most powerful interoperability with all of the aforementioned switching architectures including Just-in-Time (JIT) signaling.
The inventive switching architecture utilizes well-established arrayed waveguide grating routers with wavelength converters at the edges. There is no active component at the core, and the number of active components at the edges scales as 2N where N is a product of the total number of ports and the total number of wavelengths. Hence, the power dissipation scales as 2axe2x80x2N where axe2x80x2 is the power dissipation of the optical wavelength converter to be discussed later. This is a significant improvement over electronic terabit switches which scale as 3aN+bN2, wherein a redundant number of transponders and transistors limit the scalability and performance due to power dissipation exceeding 10 kW for terabit routers.
The inventive optical router uses advanced wavelength conversion technology to effectively achieve three methods of contention resolution in the router: deflection in wavelength, deflection in space, and buffering in time. One or a combination of the three contention resolution schemes can be utilized in the optical router to achieve high throughput.
The optical router also interfaces the local network to the Supernet, and adaptive congestion management will be achieved by early detection of network conditions. Constant communications and signaling linking the Supernet and local area networks (LANs) will be available with the present invention. The end users will benefit from high throughput and minimum delay of the network realized by the optical router. Support of priority based class-of-service (CoS) and on-demand quality of service (QoS) will provide users with flexible and cost-effective utilization of the available network capacity.
An object of the invention is to provide for ultra-low latency protocol independent packet routing.
Another object of the invention is to provide a scalable and power efficient router architecture.
Another object of the invention is to provide innovative optical switching technologies for contention resolution and header processing.
Another object of the invention is to provide for aggregation of fine grained traffic into the Supernet.
Another object of the invention is to provide for protocol independent routing and interoperability.
Another object of the invention is to provide for end-to-end adaptive congestion management.
Another object of the invention is to provide an optical router capable of routing packets with ultra-low latency and high throughput.
Another object of the invention is to provide for innovative optical switching techniques to achieve packet forwarding at very high data rates.
Another object of the invention is to provide a scalable architecture for an optical router.
Another object of the invention is to provide an ultra-low latency, protocol-agile optical router that can potentially scale beyond 1024 by 1024 in connectivity and petabit per second switching capacity.
Another object of the invention is to achieve optical monitoring of traffic and signal degradation in the network.
Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.